Revision of the Arctic group of species of the family Elpidiidae (Elasipodida, Holothuroidea)

Abstract

Species of the family Elpidiidae are the only representatives of elasipodid holothurians in the Arctic. To date, four species have been recognized in the Arctic basin: Elpidia glacialis Théel, 1876, Elpidia heckeri Baranova, 1989, Irpa abyssicola Danielssen & Koren, 1878 and Kolga hyalina Danielssen & Koren, 1879. The taxonomy of these species is not well known: Elpidia glacialis and Kolga hyalina are regarded tentatively as a combined species and Elpidia heckeri and Irpa abyssicola were known only from single localities. Three known species are recognized in the examined material: Elpidia glacialis, Elpidia heckeri and Kolga hyalina. One species appears to be new to science: Elpidia belyaevi sp. nov. Irpa abyssicola was not found. A lectotype has been designated for Kolga hyalina. Diagnoses of all examined species have been revised. Elpidiids from the deeper parts of the Arctic Ocean, determined previously as Elpidia glacialis, are identified as Elpidia heckeri or Elpidia belyaevi sp. nov. All Arctic specimens of Kolga are referred to Kolga hyalina. Distribution patterns and vertical ranges of all examined species have been clarified. Zoogeographical aspects are discussed.

Keywords:

• Arctic elpidiid holothurians
• distribution
• Elpidiidae
• key to identification
• new species
• taxonomy

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Acknowledgements

This work would have been impossible without the guidance and critical comments of Dr Andrey V. Gebruk. I am also thankful to Dr Alexei V. Smirnov, Dr Jon A. Kongsrud, Dr Endre Willassen, Dr Claus Nielsen, Dr Karin Sindemark, Dr David Billett and Dr Karen Juterzenka for providing material. Special thanks to Dr Alexander Mironov, Dr Alexei V. Smirnov and Nataliya Budaeva for their help and critical comments. Thanks are also due to Professor Alan Southward, Dr Tony Rice and Dr David Pawson for editing the style of English. This work was in part supported by a mini-grant of the ArcOD (Arctic Ocean Diversity), a project of the Census of Marine Life programme. A visit to the Bergen Museum of Zoology was funded by the Research Council of Norway.

Notes

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark